208685431 has 2 divisors, whose sum is σ = 208685432. Its totient is φ = 208685430.

The previous prime is 208685381. The next prime is 208685437. The reversal of 208685431 is 134586802.

It is a happy number.

208685431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 208685431 - 2⁹ = 208684919 is a prime.

It is a super-2 number, since 2×208685431² = 87099218223311522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208685437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104342715 + 104342716.

It is an arithmetic number, because the mean of its divisors is an integer number (104342716).

Almost surely, 2^208685431 is an apocalyptic number.

208685431 is a deficient number, since it is larger than the sum of its proper divisors (1).

208685431 is an equidigital number, since it uses as much as digits as its factorization.

208685431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 208685431 is about 14445.9486015976. The cubic root of 208685431 is about 593.1493291382.

The spelling of 208685431 in words is "two hundred eight million, six hundred eighty-five thousand, four hundred thirty-one".